I think it is very natural for a new person to be scared when investing in the first place. But you have to take care that he does not sell his investment out of fear. As time goes by, a person will gain more experience, and after a while, he will not be afraid of falling, but will learn to use it.
Of course, it's a norm for new investors to have doubt about investing in bitcoin and this is why any new investors that doesn't have confidence in bitcoin should start with a little amount as low as $10 and above from his discreationary income. If he continues buying every week with DCA, he will be learning and having more experience about the market which will keep on building his confidence gradually as he is building his portfolio too.
After one year or more when he has gained good confidence in bitcoin, he can increase the amount that he is using for his weekly DCA and invest aggressively in order to cover up those times that he was investing with little amount because of lack of confidence in bitcoin. It is better to get started with little amount and be a low coiner than a no coiner.
Finally, as we are investing in Bitcoin, let's not forget to stack up a very good emergency funds that is capable enough to withstand any emergency situation that arises, because if our emergency funds are not large enough to carry some real life emergencies, we may be forced to temper with our holdings, so let's our emergency funds be big enough to combat any unforeseen circumstances that comes our way.
The size of your emergency funds should be at least 3-6 months of your discretionary income. When you have used part of it to solve a real life emergency, it should be replaced.